If you write a 1
followed by 6 zeros,
you get 1,000,000 = one million.

If you write a 1
followed by 9 zeros,
you get one billion!

It's your turn.
Try writing out one billion in the box below:

Takes time, right? And astronomers
often deal with even larger numbers such as a trillion (12 zeros) and
a quadrillion (15 zeros). So, when astronomers write numbers with lots
of zeros, they use a shorthand called scientific
notation. Instead of writing out a 1 followed by 9 zeros,
they write a billion like this: 109.